Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/3631—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with a hook and a transversal locking element
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/364—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat using wedges
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/3663—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat hydraulically-operated
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
  • E02F9/2267—Valves or distributors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T403/00—Joints and connections
  • Y10T403/59—Manually releaseable latch type
  • Y10T403/598—Transversely sliding pin

Definitions

• the present invention relates to a device for detachable coupling of an implement and the operating arm of an excavator together, said implement having an upper side with a forward edge facing the operating arm, said device comprising an attachment member which is supported by the stick and operating cylinder of the operating arm and comprises a shaft journalled horizontally at the stick, a shaft journalled horizontally at the operating cylinder, said shafts being parallel to and arranged at a predetermined distance from each other, and a hydraulic locking member comprising a hydraulic cylinder and a control unit for supplying the hydraulic cylinder with a predetermined operating pressure via a locking connection and an opening connection, which hydraulic cylinder has double pistons with piston rods facing away from each other which can be inserted and withdrawn to opening and locking position, the free outer end parts of said piston rods having a surface sloping outwardly to form locking wedges, each of the pistons defining a rear pressure chamber that forms the plus side of the piston, and a forward pressure chamber that forms the minus side of the piston, wherein the pressure
• a device known as a quick-coupling, with hydraulic locking members of the type described above is known through EP-0 139 652, see Figure 8.
• the known device lacks satisfactory locking if a fault should occur in the hydraulic system and its locking wedges are unprotected and may therefore be damaged in inoperative positions. This may result in poorer locking function which in turn may deteriorate the influence of the link arms on the coupling member so that contact between the support surfaces of said counter-supports is insufficient and play occurs between them. Neither is the known locking member easy to install.
• SE-B-454 192 shows a similar quick-coupling but this lacks a hydraulic locking member.
• EP-0 448 788 describes a quick-coupling with a hydraulic locking member but lacks the two attachment members which are significant for the quick-coupling described in
• EP-0 139 652 and according to the present invention with cooperating counter-supports, and also lacks a locking member with locking wedges to transfer compressive force at said counter-supports and eliminate play at their contact surfaces. No auto-adjustment of the locking positions of the locking pistons can therefore be obtained with the known locking member since wear appears gradually on the movable surfaces. It will be understood that the problem of play at opposing movable surfaces increases with increased wear.
• the object of the present invention is to eliminate the problems discussed above and provide an improved device of the type described in the introduction, with a hydraulic locking member that ensures locking even if a fault should arise in the hydraulic system, where the locking wedges are protected from external influence in inoperating positions, which is easy to install, and which is self-adjusting upon wear in the contact surfaces so that play is eliminated and efficient locking and coupling functions are ensured even after extended use.
• the hydraulic cylinder is loosely mounted in corresponding, opposing openings in the link arms to form loose connections without locking engagement preventing axial movement of the hydraulic cylinder
• - cooperating stop members are arranged on the hydraulic cylinder and at least one link arm to prevent rotation of the hydraulic cylinder in said openings
• control unit is arranged to continuously supply the pressure chambers on the plus sides of the pistons with said predetermined operating pressure even when the locking wedges assume their withdrawn locking positions
• control unit is arranged to supply the pressure chambers on the minus sides of the pistons with said predetermined operating pressure even when the locking wedges are moved from opening position to locking position and when the locking wedges assume their locking positions to achieve a controlled, reduced locking action of the locking wedges corresponding to the area difference on the plus and minus sides of the pistons
• a pilot-controlled non-return valve is arranged in the locking connection between the control unit and the pressure chambers on the plus sides of the pistons, the non-return valve being openable to permit emptying of the pressure chambers on the plus sides of the pistons through the influence of said predetermined operating pressure, the non-return valve being connected via a branch connection to said opening connection for supplying said predetermined operating pressure when the locking connection is disconnected.
• Figure 1 shows schematically a bucket from above.
• Figure 2 shows a coupling device from the side.
• FIG 3 shows from above the operating-arm attachment member of the coupling device according to Figure 2.
• Figure 4 shows in section a first embodiment of the hydraulic locking member of the coupling device according to Figure 2 in operative, locking state.
• Figure 5 shows the locking member according to Figure 4 in inoperative, opened state.
• Figure 6 is a circuit diagram for the locking member according to Figure 4 and its control unit.
• Figure 7 shows a section through a second embodiment of the hydraulic locking member according to the invention.
• Figure 8 shows an end view of the locking member according to Figure 7.
• Figure 9 shows a section through a third embodiment of the hydraulic locking member according to the invention, with its control unit set to open the locking member.
• Figure 10 shows the locking member and control unit in operative locking state.
• FIG. 1 show the bucket 1 of an excavator which is provided on its upper side 2 facing away from the digging edge, with an attachment member 20 to a quick-coupling.
• This bucket attachment member 20 comprises a coupling member in the form of two inwardly facing hooks 4, 5, spaced from each other, which are welded to the upper side 2 at the forward edge 6 of the opening of the bucket 1.
• the inwardly facing hooks are provided with functional support surfaces 9, concave or semi-cylindrical in shape, with predetermined radii to achieve intimate cooperation with corresponding support surfaces on an attachment member 25 supported by the operating arm of the excavator, as will be described below.
• the two support surfaces 9 are aligned with each other and perpendicular to the plane of symmetry of the bucket .
• the bucket attachment member 20 comprises two locking elements 80, 81 provided with openings 82, 83 aligned with each other and having inclined support surfaces 90 which slope downwardly-outwardly.
• the bucket attachment member 20 also comprises two heel-shaped counter-supports 16, 17 welded to the upper side 2 and arranged between the locking elements and hooks 4, 5, in the vicinity of the former.
• Each counter-support 16, 17 is provided with a flat, functional support surface 18, 19, these support surfaces lying in the same plane and inclining inwardly towards the hooks 4, 5 for cooperation with corresponding support surfaces 40 on the operating-arm attachment member 25, as will be explained below.
• the operating arm of the excavator comprises a stick (not shown) and a hydraulic operating cylinder (not shown) arranged on its front side (facing away from the excavator) .
• the stick supports a horizontal shaft 23 at its free end, the shaft pivotably supporting the bucket 1 and thus forming the centre of pivoting of the bucket, while said hydraulic cylinder directly or indirectly via links, supports a horizontally arranged shaft 24 lying parallel with the shaft 23 of the stick and thus situated in front of this and indirectly joined to the bucket 1 to obtain a controlled swinging movement of the bucket about the centre of the shaft 23.
• the operating-arm attachment member 25 also comprises two parallel link arms 26, 27, each of which has a locking end part 86 and a coupling end part 87. At its locking end part 86, at a predetermined distance from the coupling end part 87, each link arm is provided with a cylindrical sleeve with a horizontal aperture to receive the shaft 24 and a lever-like press part 36 that protrudes into the rearward extension of the link arms.
• each link arm 26, 27 is provided at its locking end part 86 with a counter-support 39, shaped with said functional, flat support surface 40, arranged to abut said functional support surface 18, 19 of the counter-supports 16, 17 of the bucket attachment member with a wedge-producing action.
• Said functional support surfaces 18, 19 and 40 incline towards the hooks 4, 5 and have the same inclination.
• the support surfaces 18, 19 and 40 of the counter-supports preferably slope so that their extended planes form an acute angle of from 20° to 65°, preferably about 40°, with a centre plane extending through the centre of the shafts 23, 24.
• the counter-support 39 is arranged immediately below said sleeves.
• Each link arm 26, 27 is also provided or constructed at its coupling end part 87 with a shaft carrying sleeve 88 having a horizontal aperture for receipt of the shaft 23.
• the sleeve 88 is cylindrical and provided externally with a functional, semi-cylindrical support surface 89 extending transversely or axially (in relation to the shaft 23), and having a predetermined radius corresponding to the radius of the semi-circular support surfaces 9 on the hooks 4, 5, so that maximum contact is achieved between these support surfaces.
• the support surfaces 9 of the hooks encompass a sector angle within the interval 45°-180°.
• the attachment member 25 of the operating arm comprises a locking member 50 in the form of a cassette or ancillary device that enables simple and quick mounting in both new and existing quick-couplings.
• the locking member 50 comprises a hydraulic cylinder 51 containing two coaxial piston rods 52, 53 arranged in one part each of the hydraulic cylinder to press the parts out and in via their opposite ends from an inner, pressed-in, inoperative position protected from external influence to an outer, operative position pressed out of the respective parts.
• the hydraulic cylinder 51 may be constructed as a single pipe. However, for ease of manufacture it is constructed of two identical cylindrical pipe sections 54, 55, the facing ends of which are welded to a central body 56 as shown in Figures 4 and 7 (omitted in Figure 6) .
• Each piston rod 52, 53 is provided at its inner end part with a piston 57, 58 and has an outer end part shaped to function as a locking wedge 59, 60.
• the locking wedge has a flat surface 61 inclining outwardly towards the centre plane of the piston rod. The most preferred inclination is 10°.
• the piston rod runs in a sealed guide 63, 64 situated in the pipe sections 54, 55 to sealingly close this, and is retained in the pipe section by means of an end lid 65, 66 screwed firmly on.
• the inner end part of the piston rods 52, 53 is provided with a coaxial cylindrical recess 67, 68 to receive the end of a compression spring 69.
• a single spring 69 is used which is tensioned between the two piston rods 52, 53 which thus receive one end each of the spring.
• the spring thus extends through a coaxial cavity 70 in the central body 56.
• two springs 69a, 69b are used, which are tensioned between the central body 56 and the piston rods 52, 53, respectively.
• the compression spring 69 in the embodiment shown in Figures 3-5 is arranged to pre-stress the piston rods 52, 53 in their outer locking positions so that these locking positions will always be ensured in the event of faults occurring in the hydraulic system during operation.
• the two compression springs 69a, 69b are arranged to pre-stress the piston rods 52 and 53, respectively, in corresponding manner .
• Each piston 57, 58 defines a first pressure chamber 71, 72 between itself and the central body 56, forming the plus side for activation of the locking wedges
• Each piston defines a second pressure chamber 73, 74 between itself and the piston-rod guides 63, 64, forming the minus side for de-activation of the locking wedges 59, 60.
• the pressure area is considerably larger on the plus side than on the minus side.
• the compressive force is transferred from the locking wedges 59, 60 to the hooks 4, 5 via the counter-supports 39, the link arms 26, 27 and their sleeves 88, which press directly against the hooks 4, 5 and the shaft 23 is therefore not affected by this compressive load.
• compressive forces appear on the exterior 89 of the sleeves 88, i.e. the support surfaces towards or away from the support surfaces 9 of the hooks, and on the interior of the sleeves towards or away from the shaft 23.
• the joint is completely rigid at the support surfaces 9 of the hooks 4, 5.
• the locking member 50 comprises a control unit 41 which includes a valve block located at a suitable point on the excavator and coupled to the hydraulic system of the excavator.
• the hydraulic system may have a servo-pressure source or a system pressure source.
• the servo-pressure source is low-pressure acting, e.g. 50 bar, and can therefore be used without reduction, whereas the system pressure source is high-pressure acting and requires pressure reduction upon connection to the hydraulic cylinder.
• the control units shown in Figures 6 and 9, 10 can be connected to either type of pressure source.
• the control units shown have a gate P for connection to the system pressure source if the excavator lacks a servo-pressure system, and a gate Ps for connection to the servo-pressure system if the excavator is provided with a servo-pressure system.
• a gate T is provided for connection to a drainage tank when the locking member is to be detached from the work implement.
• the control unit 41 also has a gate A for connection to the two pressure chambers 71, 72 of the hydraulic cylinder on the plus side of the pistons 57, 58 via a hose 77 and a T-shaped connection 42 in the intermediate piece 56, which connection 42 is formed by a radial channel 75 and an axial channel 76.
• the control unit 41 is also provided with a gate B for connection to the two pressure chambers 73, 74 of the hydraulic cylinders on the minus side of the pistons 57, 58 via a hose 78 and two branch connections 43, 44, which branch connections are suitably surrounded by a casing or other protective element to prevent them being damaged.
• a pilot-controlled non-return valve 45 which is also connected via a connection 46 to the flow path formed by the hose 78 and one of the branch connections 43, 44.
• the control unit 41 comprises a pressure-reducing valve 98 arranged in the valve block, which can be pre-set at a desired lower pressure, e.g. 50 bar, and a directional valve 97.
• a channel 47 connects gate P to gate B, in which channel 47 the pressure-reducing valve 98 is arranged in order to emit a simulated servo-pressure upon locking and opening of the hydraulic locking member 50 when the excavator is not equipped with a servo-pressure system.
• the pressure-reducing valve 98 thus reduces the incoming system pressure at gate P to the pre-set value and the remaining oil is thus diverted to the drainage tank via a drainage channel 48 and gate T.
• the directional valve 97 is connected to gate A via a channel 49 and with gate T via a drainage channel 28, to which the drainage channel 48 of the pressure-reducing valve 98 is connected.
• the directional valve 97 is also connected to gate P via a channel 31 which is connected to channel 47 at a point downstream of the pressure-reducing valve 98.
• a channel 32 from gate Ps is also connected at the same point, which channel 32 is provided with a non-return valve 33.
• the directional valve 97 has a first closable passage 29 and a second closable passage 30.
• non-activated state of the directional valve 97 its first passage 29 opens a flow path between gate P and gate A in order to set the locking member 50 in locking function, and this flow path is maintained continuously so that the locking member 50 producing a wedge action becomes self-adjusting when wear occurs on the wedge surfaces and other contact surfaces of the two attachment members 20, 25.
• activated state of the directional valve 97 its other passage 30 opens a flow path between gate A and gate T in order to set the locking member 50 in opening function by allowing oil to flow from the pressure chambers 71, 72 along this flow path via the T-shaped connection 42 and hose 77, whereupon the pilot-controlled non-return valve 45 is opened for drainage purposes of the pressure exerted on it via the connection 46 still communicating with gate P.
• each end part of the hydraulic cylinder 51 On the outer side of each end part of the hydraulic cylinder 51 a support ring 91, 92 is arranged at a predetermined distance from the outer end of each end part.
• the hydraulic cylinder 51 is mounted at the two link arms 26, 27 which are provided with opposing cylindrical openings 93, 94 in which the cylindrical pipe sections 54, 55 are received in a loose connection, i.e. without mechanically fixed connection between the actual link arms 26, 27 and the actual pipe sections 54, 55, in order to avoid built-in stresses in the operating-arm attachment member 25. No welding or screwing is performed, therefore, and the connection is quite loose and thus not rigid.
• the distance between the two support rings 91, 92 thus corresponds to the distance between the link arms 26, 27 which are to abut against the support rings 91, 92.
• one support ring 91 is provided with a radial extension 95 with a slot 96 to receive a holding element (not shown) , provided or applied on the inner side of the opposing link arm 26.
• Such stop members i.e. at the position of the holder element in the slot 96, prevent the hydraulic cylinder 51 from turning, thereby ensuring that the positions in circumferential direction of the locking surfaces 61, 62 of the locking wedges 59, 60 are always maintained.
• gate P When the hydraulic locking member is to be opened, gate P is pressurized and the oil passes the pressure-reducing valve 98 which reduces the system pressure to the pre-set pressure, the remaining oil being drained to a tank via gate T.
• the directional valve 97 is activated and the incoming oil is conveyed through gate B and into the two minus connections of the hydraulic cylinder, and via the pilot-controlled non-return valve 45 fitted in the central body 56 of the hydraulic cylinder so that the oil in the plus chambers 71, 72 can be drained to a tank.
• the oil fills the two minus chambers 73, 74 and opens the locking member 50. This produces a force in the opening function which is approximately 50% greater than when the locking member is locked.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Shovels (AREA)
• Earth Drilling (AREA)
• Mechanical Operated Clutches (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (3)

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ID=20407020

Family Applications (1)

Country Status (10)

Families Citing this family (34)

Citations (2)

Family Cites Families (1)

• 1997
  • 1997-05-21 SE SE9701887A patent/SE9701887D0/xx unknown
• 1998
  • 1998-05-13 KR KR1019997010829A patent/KR20010012863A/ko not_active Application Discontinuation
  • 1998-05-13 US US09/424,077 patent/US6231296B1/en not_active Expired - Fee Related
  • 1998-05-13 DE DE69821776T patent/DE69821776T2/de not_active Expired - Lifetime
  • 1998-05-13 WO PCT/SE1998/000881 patent/WO1998053152A1/en active IP Right Grant
  • 1998-05-13 CA CA002289516A patent/CA2289516A1/en not_active Abandoned
  • 1998-05-13 JP JP55028198A patent/JP2001525897A/ja active Pending
  • 1998-05-13 EP EP98923262A patent/EP1012407B1/de not_active Expired - Lifetime
  • 1998-05-13 AT AT98923262T patent/ATE259921T1/de not_active IP Right Cessation
  • 1998-05-13 AU AU75596/98A patent/AU724776B2/en not_active Expired

Patent Citations (2)

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